Portable evaporative cooler

ABSTRACT

A portable evaporative cooler includes a first reservoir for holding a working fluid and having an air inlet and an air outlet. A partition separates the first reservoir from a second reservoir which stores a reserve fluid. A chute curved from the partition through the second reservoir directs the flow of air from the air outlet through a curved path. A valve in the partition replenishes the working fluid from the reserve fluid in the second reservoir and is responsive to a sensor disposed within the first reservoir.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention relates to a portable-evaporative cooler, and, more specifically, to a personal, portable evaporative cooler for a vapor compression-type system that does not require a compressor.

2. Description of the Prior Art

The most common type of comfort cooler is commonly referred to as a vapor compression A/C system. The vapor compression A/C system comprises a condenser, an evaporator, a compressor, and an expansion device operating in a closed loop. A working fluid circulates within the closed loop. The working fluid enters the compressor as vapor under low pressure and the compressor compresses the vapor to form a super heated, high pressure vapor that passes through the condenser. As the vapor passes through the condenser, a blowing device moves outside air across the condenser, cooling the vapor thereby condensing the vapor to a liquid. The air moving device transfers heat from the super heated, high pressure vapor to the outside air. The condensed vapor exits the condenser as high pressure sub-cooled liquid and passes through the expansion device which lowers its pressure forming a mixture of liquid and vapor. The low pressure liquid-vapor mixture then enters the evaporator and a second blowing device moves outside air across the evaporator resulting in the evaporation of the liquid-vapor mixture. The evaporation of the liquid-vapor mixture draws heat from outside air thereby cooling the outside air. One drawback of the vapor compression A/C systems is the requirement of the two heat exchangers, two blowing devices, the working fluid, and the compressor. The vapor compression A/C systems tend to be large and bulky and are generally not portable because of the numerous components. The use of a compressor significantly impacts the weight and bulkiness of the A/C system resulting in a less portable A/C system. Moreover, the working fluids are generally not environmentally safe and may be possibly harmful or toxic if exposed to the user.

To satisfy the demand for a more portable comfort cooler, direct evaporative and indirect evaporative coolers have been used in the art. The direct evaporative cooler comprises a working fluid, such as a pool of water, and hot air passes directly over the surface of the fluid. Energy from the air is transferred for evaporating the fluid, which results in a drop of the temperature of the air. As the temperature drops, the absolute humidity of the air increases. The indirect evaporative cooler generally has a working fluid and a wet channel with a first air moving device and a dry channel with a second air moving device. The first air moving device directs a stream of air through the wet channel and the second air moving device directs air through the dry channel. The air flowing through the wet channel carries water vapor that is evaporated from the air contacting the dry channel.

Both direct and indirect evaporative coolers can be advantageous over vapor compression A/C systems since they weigh significantly less than a vapor compression A/C system due to the fewer number of components and lack of compressor. This allows for increased portability. The drawbacks to both direct and indirect evaporative coolers are the need to replenish the working fluid which is evaporated into the air passing over the working fluid during the cooling of the air. To overcome this disadvantage, portable evaporative coolers have been developed which are capable of replenishing the working fluid at remote sites. Furthermore, portable evaporative coolers have been used which are capable of replenishing the working fluid at remote sites without the need for action by the operator.

An example of a portable evaporative cooler that is capable of replenishing the working fluid at a remote site without the need for action by the operator is disclosed in U.S. Pat. No. 6,101,831 to Ciccone. The '831 patent discloses a portable evaporative cooler having a reservoir for a working fluid which has a fitting enabling the portable evaporative cooler to be connected to a working fluid source, such as a water hose. The fitting includes a valve which automatically fills the reservoir with working fluid from the external working fluid source when the water level in the reservoir is below a predetermined level.

Another example of an evaporative cooler that is capable of replenishing the working fluid at a remote site without the need for action by the operator which additionally utilizes a first and second reservoir is disclosed in U.S. Pat. No. 4,573,490 to Kaletsky. The '490 patent discloses an evaporative cooler having a first reservoir with a working fluid regulating means for controlling the entry of working fluid into the first reservoir from an external source. The '490 patent additionally discloses a second reservoir to receive a portion of the working fluid being circulated through the system. When the working fluid in the second reservoir reaches a predetermined level, a valve located in the base of the second reservoir directs the contents of the second reservoir to the first reservoir causing the working fluid in the first reservoir to exceed a predetermined limit causing a valve located within the first reservoir to empty the working fluid from the first reservoir. The first reservoir is then refilled by the external source through the working fluid regulation means within the first reservoir.

Although the prior art discloses portable evaporative coolers that can use an external working fluid source to replenish the working fluid, a demand exists for a portable evaporative cooler that is able to replenish the working fluid from an internal source without the aid of an external working fluid source. Furthermore, the prior art does disclose an evaporative cooler utilizing a second reservoir to purge a first reservoir, but a demand still exists for a portable evaporative cooler that utilizes a second reservoir to replenish the working fluid held in the first reservoir in order to increase the portability of the evaporative cooler.

SUMMARY OF THE INVENTION AND ADVANTAGES

In accordance with the subject invention, a portable evaporative cooler has a first reservoir for holding a working fluid. The first reservoir has an air inlet for ingress and flow of air over the working fluid to exchange heat between the working fluid and the air. A second reservoir stores a reserve fluid and is separated from the first reservoir by a partition. A sensor is disposed within the first reservoir for producing a signal in the first reservoir. A valve located in the partition responds to the signal produced by the sensor and replenishes the working fluid held in the first reservoir from the reserve fluid stored in the second reservoir.

The subject invention provides a portable evaporative cooler that replenishes the working fluid held in a first reservoir with a reserve fluid stored in a second reservoir which allows the portable evaporative cooler to be used for an extended period of time independent of an external working fluid source and without the need for action by the operator.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein the FIGURE is a perspective, cross-sectional view of a portable air conditioner.

DETAILED DESCRIPTION OF THE INVENTION

A portable evaporative cooler 20 is generally shown in the FIGURE and includes a first reservoir 22 for holding a working fluid 24. The first reservoir 22 is shown as a generally rectangularly shaped first reservoir 22 having an air inlet 26 for ingress and flow of air over the working fluid 24 to exchange heat between the working fluid 24 and the air. The first reservoir 22 may include an air outlet 28 for egress and flow of air from the first reservoir 22. The working fluid 24 may be any fluid capable of heat exchange with air, such as water.

A sensor 30 is disposed within the first reservoir 22 for producing a signal in the first reservoir 22. In the preferred embodiment the sensor 30 produces a signal at a predetermined level of the working fluid 24 in the first reservoir 22. An example of such a sensor 30 is one that closes a switch or current path when the liquid reaches a level to be a conductor between contacts.

A cooling module 32 is disposed within the first reservoir 22 for cooling air flowing over the working fluid 24. The cooling module 32 receives air from the air inlet 26 of the first reservoir 22, and ejects cooled air through the air outlet 28 of the first reservoir 22. A cooling module 32 may be used which is similar to the one disclosed in FIG. 2 of co-pending U.S. application Ser. No. 11/333,904, filed Jan. 18, 2006. The cooling module 32 disclosed in U.S. application Ser. No. 11/333,904 receives air from the air inlet 26 and a fraction of the air is diverted to wet channels lined with a soaked wicking material to present the working fluid 24. This diverted air flowing through the wet channels causes evaporation of the working fluid 24 in the wet channels thereby lowering the temperature of the wet channel walls and thus cooling the air flowing through the contiguous dry channels to be ejected from the air outlet 28 of the first reservoir 22.

A second reservoir 34 stores a reserve fluid 36. The second reservoir 34 is shown as a generally rectangularly shaped second reservoir 34 with a partition 38 separating the first reservoir 22 from the second reservoir 34. The reserve fluid 36 may be any fluid capable of heat exchange with air, but is preferably the same fluid as the working fluid 24.

A cover plate 40 is disposed on the first reservoir 22 and the second reservoir 34 having an air opening 42 for receiving air from the air outlet 28 of the first reservoir 22. The cover plate 40 may include an exhaust opening 44 disposed over the first reservoir 22 for egress and flow of exhaust air from the cooling module 32 in the first reservoir 22. The exhaust opening 44 is shown as a plurality of exhaust openings 44 disposed over the first reservoir 22. Air received from the air inlet 26 passes through the cooling module 32 and a fraction of the air is diverted to the wet channels of the cooling module 32 as exhaust air to be received by the exhaust openings 44, and the remaining, cooled air is received by the air outlet 28. An exhaust hood 46 may be disposed on the cover plate 40 over the exhaust openings 44 for receiving the exhaust air steam from the exhaust openings 44. The cover plate 40 may also include a fill cap 48 disposed over the second reservoir 34 for replenishing the reserve fluid 36 in the second reservoir 34. The fill cap 48 preferably has an air passageway 50 allowing air to flow into the second reservoir 34.

A fan module 52 generally indicated is disposed adjacent the air inlet 26 of the first reservoir 22 for propelling air through the air inlet 26. The fan module 52 preferably has a plurality of fans 54 to propel air through the air inlet 26. A filter 56 is disposed adjacent the fan module 52 for filtering air flowing into the fan module 52, and an inlet cover 58 surrounds the filter 56. In the preferred embodiment illustrated in the FIGURE, the inlet cover 58 has a plurality of air inlet openings 60 for allowing air to pass through the inlet cover 58.

The portable evaporative cooler 20 is distinguished by a valve 62 in the partition 38 which is responsive to the signal produced by the sensor 30 in the first reservoir 22 for replenishing the working fluid 24 from the reserve fluid 36 in the second reservoir 34 to the first reservoir 22. The valve 62 receives a signal from the sensor 30 and replenishes the working fluid 24 held in the first reservoir 22 from the reserve fluid 36 stored in the second reservoir 34 without the need for action by the operator. A solenoid valve may be suitable for such a valve 62, but other valves 62 may work in other embodiments.

The portable evaporative cooler 20 is further distinguished by a chute 64 being curved from the partition 38 through the second reservoir 34 for directing the flow of air from the air outlet 28 in the first reservoir 22 through a curved path. The chute 64 receives cooled air from the air outlet 28 in the first reservoir 22 and directs the cooled air through a curved path to the air opening 42 in the cover plate 40.

When operating, the portable evaporative cooler 20 continuously produces cooled air without the need for an external working fluid source. Air is received through the air openings 42 in the inlet cover 58 and passes through the filter 56. The fans 54 contained within the fan module 52 propel the air into the cooling module 32 disposed within the first reservoir 22. Heat is exchanged between the air and the working fluid 24 held within the first reservoir 22. The working fluid 24 is evaporated into the air, cooling the air, and the air is separated into wet, exhaust air and dry, cooled air by the cooling module 32. The wet air is expelled from the cooling module 32 through exhaust openings 44 located in the cover plate 40 disposed above the first reservoir 22. The exhaust hood 46 receives the wet air from the exhaust openings 44. The dry air is expelled from the cooling module 32 through an air outlet 28 in the first reservoir 22. The dry air is directed through a curved path by the chute 64 to the air opening 42 in the cover plate 40. As the portable evaporative cooler 20 conditions air, the level of the working fluid 24 in the first reservoir 22 diminishes. The sensor 30 disposed in the first reservoir 22 produces a signal when the level of the working fluid 24 in the first reservoir 22 reaches a predetermined level, and a valve 62 receives the signal produced by the sensor 30. The valve 62 located in the partition 38 separating the first reservoir 22 from the second reservoir 34 causes reserve fluid 36 stored within the second reservoir 34 to replenish the working fluid 24 held in the first reservoir 22.

While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. 

1. A portable evaporative cooler comprising; a first reservoir for holding a working fluid, said first reservoir having an air inlet for ingress and flow of air over said working fluid to exchange heat between said working fluid and the air, a sensor disposed within said first reservoir for producing a signal in said first reservoir, a second reservoir for storing a reserve fluid, a partition separating said first reservoir from said second reservoir, and a valve in said partition and responsive to said signal produced by said sensor for replenishing said working fluid from said reserve fluid in said second reservoir to said first reservoir.
 2. A portable evaporative cooler as set forth in claim 1 wherein said first reservoir has an air outlet.
 3. A portable evaporative cooler as set forth in claim 2 including a chute being curved from said partition through said second reservoir for directing the flow of air from said air outlet in said first reservoir through a curved path.
 4. A portable evaporative cooler as set forth in claim 3 including a cover plate disposed on said first reservoir and said second reservoir and having an air opening for receiving air directed by said chute.
 5. A portable evaporative cooler as set forth in claim 4 wherein said cover plate has a fill cap for replenishing said reserve fluid in said second reservoir.
 6. A portable evaporative cooler as set forth in claim 5 wherein said fill cap has an air passageway.
 7. A portable evaporative cooler as set forth in claim 1 wherein said sensor produces a signal at a predetermined level of said working fluid in said first reservoir for activating said valve.
 8. A portable evaporative cooler as set forth in claim 1 including a cooling module disposed within said first reservoir for cooling air flowing over said working fluid.
 9. A portable evaporative cooler as set forth in claim 1 including a fan module disposed adjacent said air inlet of said first reservoir for propelling air through said air inlet.
 10. A portable evaporative cooler as set forth in claim 9 wherein said fan module has a plurality of fans.
 11. A portable evaporative cooler as set forth in claim 9 including a filter disposed adjacent said fan module for filtering air flowing into said fan module.
 12. A portable evaporative cooler as set forth in claim 11 including an inlet cover surrounding said filter and having a plurality of air inlet openings.
 13. A portable evaporative cooler as set forth in claim 1 including a cover plate disposed on said first reservoir and said second reservoir having an air opening and a plurality of exhaust openings disposed over said first reservoir for egress and flow of exhaust from said first reservoir.
 14. A portable evaporative cooler as set forth in claim 13 including an exhaust hood disposed on said cover plate for receiving air from said exhaust openings.
 15. A portable evaporative cooler as set forth in claim 13 wherein said cover plate has a fill cap for replenishing said reserve fluid in said second reservoir.
 16. A portable evaporative cooler as set forth in claim 15 wherein said fill cap has an air passageway.
 17. A portable evaporative cooler comprising; a first reservoir for holding a working fluid, said first reservoir having an air inlet for ingress and flow of air over the working fluid to exchange heat between the working fluid and the air and an air outlet, a sensor disposed within said first reservoir for producing a signal at a predetermined level of said working fluid in said first reservoir, a cooling module disposed within said first reservoir for cooling air flowing over said working fluid, a second reservoir for storing a reserve fluid, a partition separating said first reservoir from said second reservoir, a cover plate disposed on said first reservoir and said second reservoir and having an air opening and a plurality of exhaust openings disposed over said first reservoir for egress and flow of exhaust from said cooling module in said first reservoir, an exhaust hood disposed on said cover plate for receiving exhaust from said exhaust openings, said cover plate having a fill cap for replenishing said reserve fluid in said second reservoir, said fill cap having an air passageway, a fan module having a plurality of fans disposed adjacent said air inlet of said first reservoir for propelling air through said air inlet, a filter disposed adjacent said fan module for filtering air flowing into said fan module, an inlet cover surrounding said filter and having a plurality of air inlet openings, a valve in said partition and responsive to said signal produced by said sensor for replenishing said working fluid from said reserve fluid in said second reservoir to said first reservoir, and a chute being curved from said partition for directing the flow of air from said air outlet in said first reservoir through a curved path to said air opening in said cover plate. 